[QUOTE=Epimetheus]
Anyway, if you were comparing two digital cameras, what things would you look for other than MP? Will the salesperson know the size of the pixels?
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A good salesperson should know the type and size of the sensor, at least for the most commonly sold models. Of course, you might not find even this level of knowledge if you get your camera at Best Buy. A proper camera store, however, should have staff who know about this stuff.
Dervorin has given some good points about things to look for. Remember, also, that it’s not just about image quality, but about what exactly it is that you want your camera to do for you. If most of your images stay in digital form, and you rarely print anything out, then extremely high quality may not even be very important, because the high-quality output of expensive digital cameras is most noticeable in print.
As i mentioned in an earlier post, i have a Minolta Dimage 7Hi that i bought about four years ago. I like the camera a lot, and it’s served me well, but one thing i really miss is the accurate autofocus that i had with my old autofocus SLR. My Minolta has quite a bit of trouble focusing in low-contrast situations, and you can forget about capturing fast action. If you want to do this sort of thing, then an SLR is virtually essential.
As Dervorin said, low-light performance can be an issue, and is helped dramatically by larger sensors. My camera produces way too much noise (digital variations leading to reduced image quality) if i set the ISO above 200, but newer SLRs can take clean pictures up to ISO1600. This dramatically increases your picture-taking possibilities.
The thing is, there are trade-offs to be made in all these areas, as there usually are when buying electronics. SLRs are better in most cases, but they are also heavier and larger. One reason i traded my old film SLR in for my digital is that the SLR system that i had (two bodies, six lenses) was so large that i hardly ever carried it anywhere. While the digital might have some limitations, it’s small enough that i actually use it. Also, i live in the US and my family is in Australia, so it’s nice to be able to put pictures on the web for them to see.
While a salesperson might, depending on the store, be able to help you through the myriad options you need to consider when selecting a digital camera, i think you can get all the information you need on the web. If you want an excellent, one-stop location for digital camera information, you really can’t go past the Digital Photography Review website. They have in-depth reviews on hundreds of cameras, which include downloadable full-resolution image samples that allow you to compare the actual output of the different cameras. The reviews also have excellent discussion of factors such as ergonomics, controls, ease of use, menus, displays, etc., etc. The full specs for each camera are listed, including things like sensor size, type, etc., so you can compare models.
Even better, DP Review also has an excellent Glossary, which explains in layperson’s language many of the technical terms that are associated with digital photography.
[QUOTE=Epimetheus]
Also, is there a similar difference between 35mm film cameras? If you wanted to get as good resolution from a digital camera as you would from a mid to upper range 35mm camera, what size pixels and how many would you need?
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If you’re actually in a lab comparing the output of digital cameras to the output, on high-quality slide film, of film cameras, film still wins the battle in most cases. When Canon released their flagship EOS1Ds Mark II (16 megapixel, full frame 36x24mm sensor), one review i read said that this was the first digital camera they had tested that actually beat the resolution of film in the lab tests. But the Mark II is about $8,000 for the body alone, and isn’t really an option for anyone except professionals and the rich.
In the real world that the rest of us inhabit, whether a digital camera is as good as a film camera really depends on your needs.
If all you ever print out is 6x4 inch glossies for the family album, a decent point-and-shoot will give you picture quality that will be just as good as a regular film camera. This is not to say that the absolute quality of the images is as good, but that you probably won’t notice any differences in a 6x4 print. And, as i said above, if you only look at your pictures on a computer, the difference is even smaller, because computer monitor resolution is only 72 pixels per inch, far below the 300dpi recommended for good prints.
The thing is that many of the tests that photography review sites and magazines do in order to assess a camera’s image quality are almost meaningless for most people’s real world situations. For example, you will see lens reviews that compare the ability of different lenses to resolve fine detail, and these reviews will comment on differences as small as 2 or 3 lines per millimeter (lpm) in the resolving power of the lens. But while such criteria are interesting and important in some ways, the fact is that, unless you’re making massive enlargements, you will never notice such differences. Similarly, in the resolution test i discussed above between the Canon EOS1 Ds and the film cameras, the differences were so small that they needed large magnifiers to see them. The best thing to do is to ask yourself what you need your pictures for, and buy a camera that will do what you need.
Even if you do want better images and more control than is offered by point and shoot cameras, you don’t have to spend a fortune anymore. In most situations below professional level, an entry-level or mid-level digital SLR (Canon EOS 400D, Canon EOS 30D, Nikon D50, Nikon D70/D80) is more than powerful enough for even the most discerning eye, and you can now get a Canon 400D or a Nikon D50 with two lenses for less money than i paid for my Minolta four years ago.
[QUOTE=Epimetheus]
I’m pretty ignorant of photography, so I have no real sense of comparison between the two. My 3.0 MP camera looks better to me (on screen of course, I never print my pictures), than my dads old 150 dollar camera (the prices were relative to the length of time the cameras were on the market).
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And that’s the key. If it looks good enough to you, and you’re never going to print the pictures anyway, then why worry? Of course, it’s always nice to have something better, and you can get very good digital cameras for reasonable prices now, but ask yourself if a bigger and better camera would be overkill, and if you’ll actually use it. This is an especially important question if you’re thinking making the move to an SLR. They are considerably harder to take to a party or on vacation than a small point-and-shoot camera, and having the best camera in the world won’t help your photography if you leave it behind because it’s too bulky.
